DFL2500-MIB

MIB Reference — IPNetwork Monitor · Updated October 05, 2026

All MIBs › DFL2500-MIB

Organization: D-Link Corporation

Last Updated: 2010-09-02

Category: VPN and Security, Vendor: D-Link

Description: Manages D-Link DFL-2500 enterprise firewall configuration, policies, and VPN tunnels.

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What Is DFL2500-MIB?

DFL2500-MIB is a D-Link vendor MIB for the DFL-2500 series NetDefend enterprise firewall/UTM appliance, part of D-Link's network security product line. It exposes system performance metrics (CPU load, throughput), connection-state counters, and per-interface statistics for the firewall, alongside its broader role managing firewall policies and VPN tunnel configuration. For monitoring it is heavily used to track hardware/software load status: dfl2500SysCpuLoad reveals processor load on the appliance, dfl2500SysBuffUse shows buffer/memory pressure, and dfl2500SysConns plus the various protocol state counters (TCP SYN/open/fin, UDP, ICMP) reveal live connection-table health and potential attack conditions such as SYN floods. It is a self-contained proprietary enterprise MIB but conceptually parallels standard IF-MIB interface statistics for its dfl2500IfStatsTable. It is deployed on D-Link DFL-2500 firewall appliances protecting small-to-medium enterprise network perimeters, including sites terminating VPN tunnels. Engineers can download the DFL2500-MIB file directly to load it into their MIB browser.

IPNetwork Monitor allows you to monitor SNMP objects defined in DFL2500-MIB. Use the built-in SNMP Monitoring Browser to explore available variables, view their current values and descriptions, and select the objects you want to monitor. You can then create SNMP monitors, configure thresholds, and receive alerts when monitored values change.

Supported Devices

  • D-Link DFL-2500 NetDefend firewall/UTM appliance

Monitoring Examples

A security operations team would poll dfl2500SysCpuLoad and dfl2500SysBuffUse to detect the firewall appliance becoming overloaded, and would watch dfl2500SysPscTcpSyn against dfl2500SysPscTcpOpen to spot a SYN-flood pattern where SYNs vastly outnumber completed opens, indicating a possible denial-of-service attack. Polling dfl2500SysConns over time establishes a baseline for normal connection-table size, so a sudden spike would trigger an alert. The dfl2500IfStatsTable would be walked per interface to correlate forwarded packet/bit rates (dfl2500SysForwardedBits/Packets) with expected traffic patterns across the firewall's network interfaces.

What Can Be Monitored

  • CPU load
  • buffer/memory usage
  • active connection count
  • TCP SYN/open/fin packet counters (attack detection)
  • forwarded traffic (bits/packets)
  • per-interface statistics
Imported Objects

From SNMPv2-CONF

MODULE-COMPLIANCE
OBJECT-GROUP

From SNMPv2-SMI

Counter32
Counter64
Gauge32
Integer32
MODULE-IDENTITY
OBJECT-TYPE
enterprises

From SNMPv2-TC

DisplayString

How to Use in IPNetwork Monitor

Example using dfl2500SysForwardedBits OID:

Select a D-Link firewall/UTM appliance as the target host to create a monitor — the SNMP service should be up and running on it. Click New Monitor, then check SNMP Custom on the Favorites tab, click Next, and confirm the host. On the next page, click Select... to open the built-in SNMP MIB Browser and type dfl2500SysForwardedBits into the Find box to locate it in the OID tree, then select it and click OK. The number of bits forwarded through the gateway. On the monitor's Main parameters page you can set the target's SNMP port (default 161), credentials, polling interval, and other settings — see the SNMP Monitor help for details. On the State conditions and Alerting tabs, configure when the monitor should change state and trigger an alert; since this is a Counter32-type OID, Value bounds is the most useful condition here — trigger an alert if the counter increases sharply between polls relative to its normal baseline, since an unexpected spike often reflects a real change in traffic or activity. Click Finish to create the monitor; you can adjust any parameter later.
OIDs

RFC description

Monitors D-Link DFL-2500 firewall system statistics including CPU load, memory usage, and connection metrics.

Start monitoring D-Link firewall/UTM appliances with a free 30-day trial of IPNetwork Monitor. Import MIBs, browse SNMP OIDs, create custom SNMP monitors, configure alerts, and monitor any SNMP-enabled network device from a single console.

Download DFL2500-MIB